DE672134C - Process for the preparation of monoazo dyes - Google Patents

Description

Process for the preparation of monoazo dyes It has been found that new valuable monoazo dyes are obtained, which are particularly suitable for dyeing animal fibers, if the diazo compounds from aromatic amines of the formula wherein the benzene nucleus can also contain further substituents, combined with any azo components.

The diazo components used to build up this class of dyes have not yet been described. They can be obtained by acylation of nitrophenylaminoalkyl-co-sulfonic acids and subsequent reduction or by Acylation of arylaminoalkyl-co-sulfonic acids, nitration and subsequent reduction. The nitrophenylaminoall: yl-co-sulfonic acids used as starting compounds can be prepared 'by, for example, nitrochloric, benzenesulfonic acids with amine alkyl sulfonic acids, e.g. B. with aminoethanesulfonic acid (taurine), condensed and then the aromatically bound sulfonic acid group by heating with dilute Splitting off sulfuric acid, the external sulfonic acid group being retained, or by adding phenylalkylamino-cosulfonic acids, e.g. B. Phenyltaurine, with acyl.ierenden Treated agents and nitrated the compounds thus obtained and then reduced.

The new dyes differ from the analogous dyes, which can be prepared by the processes known from patent a96 964 and French patent 76r o39 and which do not contain a sulfonic acid group in the alkyl radical of the acylamino group in the diazo component, by their significantly greater solubility and better Drawability and partly also through better seawater and lightfastness. ' The monoazo dyes known from patent specification 39.5 636, which are particularly suitable for dyeing and printing acetate silk, are surpassed by the dyes obtainable by the present process in that the latter dyes on wool of much livelier and more yellowish shades and of much better lightfastness deliver.

Example z z 5.8 kg i - (c,) - sulfoäthylacetylamino) -q.-aminobenzene are diazotized in the usual way, and the diazo compound is in weak mineral acid agent coupled with 24 kg of 2-amino-8-oxynaphthalene-6-sulfonic acid. ..

The onoazo dye thus obtained bildep '@ after separating and drying a xofeü "i water soluble powder. He owns one Equalizing power and dyes wool or silk in very lightfast, yellowish-red tones. Example e The diazo compound prepared according to Example i is coupled in an acetic acid agent with 35 kg of 2- (['-Methoxyphenylamino) -8-oxynaphthalene-6-sulfonic acid.

A lightfast brown of great depth and opacity is obtained on wool; the monoazo dye has good leveling power.

If the coupling is carried out in the presence of sodium carbonate; so receives a more yellowish tinged brown with similar properties.

Example 3 The diazo compound prepared according to Example i is coupled one in the presence of sodium carbonate with 26 kg of i- (2'-chloro-5'-sulfophenyl) -3-methyl-5-pyrazolone.

The monoazo dye thus obtained is a yellow, water-soluble one Powder. It has good leveling properties and dyes wool in a lightfast, greenish yellow Tones.

Example q.

The diazo compound prepared according to Example i is coupled in the presence of sodium acetate with 29 kg of 2-acetylamino-8-oxynaphthalene-6-sulfonic acid.

The monoazo dye thus obtained forms after separation and drying a red, water-soluble powder and dyes wool in vivid, yellow-tinged red Shades of good lightfastness and very good leveling power.

Monoazo dyes with similar properties and a more yellowish or bluish hue are obtained by using other acylaminonaphthol mono- or disulfonic acids or naphthol mono- '@ bder-disulfonic acids as azo components. Similar monoazo dyes are obtained y #, "'if diazo compounds are used, @ alW0 in place of the acetyl radical other Acy1- remnants, e.g. B. the chloroacetyl, methoxyacetyl, phenoxyacetyl, benzene or toluenesulfoyl, or instead of the co-sulfoethyl group other co-sulfoalkyl groups, z. B. the co-sulfopropyl group, contained in the diazo component.

Example 5 32 kg of i - (w - sulfoethylbenzoylamino) -4-aminobenzene were obtained by treating ethylaminobenzene-co-sulfonic acid (phenyltaurine) with benzoyl chloride, Nitriding the compound thus obtained, for example in Eisesse and then Reduction, as usual, are diazotized. The diazo solution thus obtained is left in a solution of 32 kg of 2-phenylamino-8-oxynaphthalene-6-sulfonic acid mixed with excess sodium carbonate to run.

The monoazo dye thus obtained forms after salting out and drying a dark, very well-water-soluble powder, the wool or silk in very deep Dyes shades of brown with very good fastness properties.

Claims (1)

PATRNTIINSPRUCI-i: Process for the preparation of monoazo dyes, characterized in that the diazo compounds are obtained from aromatic amines of the formula in which the benzene nucleus can also contain further substituents, combined with any azo components.